Retinal Biomarkers in Parkinson´s Disease

April 8, 2025 updated by: Thorunn Scheving Eliasdottir, Landspitali University Hospital

Retinal Biomarkers in Parkinson´s Disease: Retinal Oximetry, Pattern Electroretinography (PERG), Visual Evoked Potentials (VEP) and Optical Coherence Tomography (OCT)

The goal of this observational study is to determine whether oxygen content of the retinal vessels of the eye may serve as a biomarker in Parkinson´s disease. The main questions it aims to answer are:

  1. Is retinal vessel oxyhemoglobin saturation and vessel width altered in people with Parkinson´s disease?
  2. Is the thickness of the retinal nerve fiber layer altered in people with Parkinson´s disease?
  3. Is the response of ganglion cells of the inner retina and the visual cortex altered in people with Parkinson´s disease?

The study procedure is threefold. The participants will:

A. Sit in front of a screen and focus on a red dot of its middle. A simple recording electrodes are applied on the cornea, forehead and scalp for the electrophysiological measurements. Prior to this procedure a topical anesthetic gel is applied to numb the eye to prevent discomfort from placement of the corneal electrodes.

B. Undergo general eye examination and optical coherence tomography (OCT) to measure the retinal tissue thickness. Prior to eye examination,eye drops are applied into the eyes to enlarge the pupils C. Sit in front of a fundus camera for obtaining images of the retinal vessels to measure oxygen saturation and the vessel width

Researchers will compare the obtained measurements with age- and gender matching of healthy controls.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
60

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Iceland
      • Reykjavik, Iceland, 101
        • Ophthalmic Outpatient Department Landspitali UH

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

People with confirmed parkinsons disease Stage 0-3 on the Hohen and Yahr scale

Description

Inclusion Criteria:

  • Confirmed Parkinson Disease

Exclusion Criteria:

  • Eye disease
  • Diabetic Mellitus
  • Chronic Obstructive Pulmonary Disease (COPD)
  • Other Neurological Disease
  • Smoking on a daily basis

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Retinal vessels oxyhemoglobin saturation
Time Frame: Baseline. On the visit to the ambulatory Opthalamic department at Landspitali
Obtained by retinal oximetry
Baseline. On the visit to the ambulatory Opthalamic department at Landspitali

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Vessel width of retinal arterioles and venules
Time Frame: Baseline. On the visit to the ambulatory Opthalamic department at Landspitali
Obtained by retinal oximetry
Baseline. On the visit to the ambulatory Opthalamic department at Landspitali
Retinal nerve fiber layer thickness
Time Frame: Baseline. On the visit to the ambulatory Opthalamic department at Landspitali
Obtained by cross-sectional imaging of the retinal tissue (OCT)
Baseline. On the visit to the ambulatory Opthalamic department at Landspitali
Components and waveform of VEPs
Time Frame: Baseline. On the visit to the ambulatory Opthalamic department at Landspitali
Pattern electroretinogram (PERG)
Baseline. On the visit to the ambulatory Opthalamic department at Landspitali
Pattern electroretinograms (PERGs)
Time Frame: Baseline. On the visit to the ambulatory Opthalamic department at Landspitali
Amplitude of the visual evoked potential response
Baseline. On the visit to the ambulatory Opthalamic department at Landspitali

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Landspitali University Hospital

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University of Iceland
Reykjalundur Rehabilitation

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Thorunn S Eliasdottir, PhD, CRNA, University Hospital of Iceland and University of Iceland. Reykjalundur
  • Principal Investigator: Thorunn S Eliasdottir, PhD, CRNA, Landpitali the University Hopital of Iceland
  • Principal Investigator: Thorunn S Eliasdottir, PhD, CRNA, University of Iceland
  • Principal Investigator: Soley Thrainsdottir, MD, PhD, Reykjalundur

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 10, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 31, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 8, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 15, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 15, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 8, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • VSN-22-129

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings